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[PATCH] slab: fix sparse warning
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / security / selinux / hooks.c
CommitLineData
1da177e4
LT		 1/*
2 * NSA Security-Enhanced Linux (SELinux) security module
3 *
4 * This file contains the SELinux hook function implementations.
5 *
6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
7 * Chris Vance, <cvance@nai.com>
8 * Wayne Salamon, <wsalamon@nai.com>
9 * James Morris <jmorris@redhat.com>
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
14 * <dgoeddel@trustedcs.com>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2,
18 * as published by the Free Software Foundation.
19 */
20
21#include <linux/config.h>
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/ptrace.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
28#include <linux/security.h>
29#include <linux/xattr.h>
30#include <linux/capability.h>
31#include <linux/unistd.h>
32#include <linux/mm.h>
33#include <linux/mman.h>
34#include <linux/slab.h>
35#include <linux/pagemap.h>
36#include <linux/swap.h>
37#include <linux/smp_lock.h>
38#include <linux/spinlock.h>
39#include <linux/syscalls.h>
40#include <linux/file.h>
41#include <linux/namei.h>
42#include <linux/mount.h>
43#include <linux/ext2_fs.h>
44#include <linux/proc_fs.h>
45#include <linux/kd.h>
46#include <linux/netfilter_ipv4.h>
47#include <linux/netfilter_ipv6.h>
48#include <linux/tty.h>
49#include <net/icmp.h>
50#include <net/ip.h> /* for sysctl_local_port_range[] */
51#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
52#include <asm/uaccess.h>
53#include <asm/semaphore.h>
54#include <asm/ioctls.h>
55#include <linux/bitops.h>
56#include <linux/interrupt.h>
57#include <linux/netdevice.h> /* for network interface checks */
58#include <linux/netlink.h>
59#include <linux/tcp.h>
60#include <linux/udp.h>
61#include <linux/quota.h>
62#include <linux/un.h> /* for Unix socket types */
63#include <net/af_unix.h> /* for Unix socket types */
64#include <linux/parser.h>
65#include <linux/nfs_mount.h>
66#include <net/ipv6.h>
67#include <linux/hugetlb.h>
68#include <linux/personality.h>
69#include <linux/sysctl.h>
70#include <linux/audit.h>
6931dfc9 71#include <linux/string.h>
1da177e4
LT		 72
73#include "avc.h"
74#include "objsec.h"
75#include "netif.h"
d28d1e08 76#include "xfrm.h"
1da177e4
LT		 77
78#define XATTR_SELINUX_SUFFIX "selinux"
79#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
80
81extern unsigned int policydb_loaded_version;
82extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
83
84#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
85int selinux_enforcing = 0;
86
87static int __init enforcing_setup(char *str)
88{
89 selinux_enforcing = simple_strtol(str,NULL,0);
90 return 1;
91}
92__setup("enforcing=", enforcing_setup);
93#endif
94
95#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
96int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
97
98static int __init selinux_enabled_setup(char *str)
99{
100 selinux_enabled = simple_strtol(str, NULL, 0);
101 return 1;
102}
103__setup("selinux=", selinux_enabled_setup);
104#endif
105
106/* Original (dummy) security module. */
107static struct security_operations *original_ops = NULL;
108
109/* Minimal support for a secondary security module,
110 just to allow the use of the dummy or capability modules.
111 The owlsm module can alternatively be used as a secondary
112 module as long as CONFIG_OWLSM_FD is not enabled. */
113static struct security_operations *secondary_ops = NULL;
114
115/* Lists of inode and superblock security structures initialized
116 before the policy was loaded. */
117static LIST_HEAD(superblock_security_head);
118static DEFINE_SPINLOCK(sb_security_lock);
119
120/* Allocate and free functions for each kind of security blob. */
121
122static int task_alloc_security(struct task_struct *task)
123{
124 struct task_security_struct *tsec;
125
89d155ef 126 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4
LT		 127 if (!tsec)
128 return -ENOMEM;
129
1da177e4
LT		 130 tsec->magic = SELINUX_MAGIC;
131 tsec->task = task;
132 tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
133 task->security = tsec;
134
135 return 0;
136}
137
138static void task_free_security(struct task_struct *task)
139{
140 struct task_security_struct *tsec = task->security;
141
142 if (!tsec || tsec->magic != SELINUX_MAGIC)
143 return;
144
145 task->security = NULL;
146 kfree(tsec);
147}
148
149static int inode_alloc_security(struct inode *inode)
150{
151 struct task_security_struct *tsec = current->security;
152 struct inode_security_struct *isec;
153
89d155ef 154 isec = kzalloc(sizeof(struct inode_security_struct), GFP_KERNEL);
1da177e4
LT		 155 if (!isec)
156 return -ENOMEM;
157
1da177e4
LT		 158 init_MUTEX(&isec->sem);
159 INIT_LIST_HEAD(&isec->list);
160 isec->magic = SELINUX_MAGIC;
161 isec->inode = inode;
162 isec->sid = SECINITSID_UNLABELED;
163 isec->sclass = SECCLASS_FILE;
164 if (tsec && tsec->magic == SELINUX_MAGIC)
165 isec->task_sid = tsec->sid;
166 else
167 isec->task_sid = SECINITSID_UNLABELED;
168 inode->i_security = isec;
169
170 return 0;
171}
172
173static void inode_free_security(struct inode *inode)
174{
175 struct inode_security_struct *isec = inode->i_security;
176 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
177
178 if (!isec || isec->magic != SELINUX_MAGIC)
179 return;
180
181 spin_lock(&sbsec->isec_lock);
182 if (!list_empty(&isec->list))
183 list_del_init(&isec->list);
184 spin_unlock(&sbsec->isec_lock);
185
186 inode->i_security = NULL;
187 kfree(isec);
188}
189
190static int file_alloc_security(struct file *file)
191{
192 struct task_security_struct *tsec = current->security;
193 struct file_security_struct *fsec;
194
89d155ef 195 fsec = kzalloc(sizeof(struct file_security_struct), GFP_ATOMIC);
1da177e4
LT		 196 if (!fsec)
197 return -ENOMEM;
198
1da177e4
LT		 199 fsec->magic = SELINUX_MAGIC;
200 fsec->file = file;
201 if (tsec && tsec->magic == SELINUX_MAGIC) {
202 fsec->sid = tsec->sid;
203 fsec->fown_sid = tsec->sid;
204 } else {
205 fsec->sid = SECINITSID_UNLABELED;
206 fsec->fown_sid = SECINITSID_UNLABELED;
207 }
208 file->f_security = fsec;
209
210 return 0;
211}
212
213static void file_free_security(struct file *file)
214{
215 struct file_security_struct *fsec = file->f_security;
216
217 if (!fsec || fsec->magic != SELINUX_MAGIC)
218 return;
219
220 file->f_security = NULL;
221 kfree(fsec);
222}
223
224static int superblock_alloc_security(struct super_block *sb)
225{
226 struct superblock_security_struct *sbsec;
227
89d155ef 228 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT		 229 if (!sbsec)
230 return -ENOMEM;
231
1da177e4
LT		 232 init_MUTEX(&sbsec->sem);
233 INIT_LIST_HEAD(&sbsec->list);
234 INIT_LIST_HEAD(&sbsec->isec_head);
235 spin_lock_init(&sbsec->isec_lock);
236 sbsec->magic = SELINUX_MAGIC;
237 sbsec->sb = sb;
238 sbsec->sid = SECINITSID_UNLABELED;
239 sbsec->def_sid = SECINITSID_FILE;
240 sb->s_security = sbsec;
241
242 return 0;
243}
244
245static void superblock_free_security(struct super_block *sb)
246{
247 struct superblock_security_struct *sbsec = sb->s_security;
248
249 if (!sbsec || sbsec->magic != SELINUX_MAGIC)
250 return;
251
252 spin_lock(&sb_security_lock);
253 if (!list_empty(&sbsec->list))
254 list_del_init(&sbsec->list);
255 spin_unlock(&sb_security_lock);
256
257 sb->s_security = NULL;
258 kfree(sbsec);
259}
260
261#ifdef CONFIG_SECURITY_NETWORK
7d877f3b 262static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
1da177e4
LT		 263{
264 struct sk_security_struct *ssec;
265
266 if (family != PF_UNIX)
267 return 0;
268
89d155ef 269 ssec = kzalloc(sizeof(*ssec), priority);
1da177e4
LT		 270 if (!ssec)
271 return -ENOMEM;
272
1da177e4
LT		 273 ssec->magic = SELINUX_MAGIC;
274 ssec->sk = sk;
275 ssec->peer_sid = SECINITSID_UNLABELED;
276 sk->sk_security = ssec;
277
278 return 0;
279}
280
281static void sk_free_security(struct sock *sk)
282{
283 struct sk_security_struct *ssec = sk->sk_security;
284
285 if (sk->sk_family != PF_UNIX || ssec->magic != SELINUX_MAGIC)
286 return;
287
288 sk->sk_security = NULL;
289 kfree(ssec);
290}
291#endif /* CONFIG_SECURITY_NETWORK */
292
293/* The security server must be initialized before
294 any labeling or access decisions can be provided. */
295extern int ss_initialized;
296
297/* The file system's label must be initialized prior to use. */
298
299static char *labeling_behaviors[6] = {
300 "uses xattr",
301 "uses transition SIDs",
302 "uses task SIDs",
303 "uses genfs_contexts",
304 "not configured for labeling",
305 "uses mountpoint labeling",
306};
307
308static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
309
310static inline int inode_doinit(struct inode *inode)
311{
312 return inode_doinit_with_dentry(inode, NULL);
313}
314
315enum {
316 Opt_context = 1,
317 Opt_fscontext = 2,
318 Opt_defcontext = 4,
319};
320
321static match_table_t tokens = {
322 {Opt_context, "context=%s"},
323 {Opt_fscontext, "fscontext=%s"},
324 {Opt_defcontext, "defcontext=%s"},
325};
326
327#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
328
329static int try_context_mount(struct super_block *sb, void *data)
330{
331 char *context = NULL, *defcontext = NULL;
332 const char *name;
333 u32 sid;
334 int alloc = 0, rc = 0, seen = 0;
335 struct task_security_struct *tsec = current->security;
336 struct superblock_security_struct *sbsec = sb->s_security;
337
338 if (!data)
339 goto out;
340
341 name = sb->s_type->name;
342
343 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
344
345 /* NFS we understand. */
346 if (!strcmp(name, "nfs")) {
347 struct nfs_mount_data *d = data;
348
349 if (d->version < NFS_MOUNT_VERSION)
350 goto out;
351
352 if (d->context[0]) {
353 context = d->context;
354 seen |= Opt_context;
355 }
356 } else
357 goto out;
358
359 } else {
360 /* Standard string-based options. */
361 char *p, *options = data;
362
363 while ((p = strsep(&options, ",")) != NULL) {
364 int token;
365 substring_t args[MAX_OPT_ARGS];
366
367 if (!*p)
368 continue;
369
370 token = match_token(p, tokens, args);
371
372 switch (token) {
373 case Opt_context:
374 if (seen) {
375 rc = -EINVAL;
376 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
377 goto out_free;
378 }
379 context = match_strdup(&args[0]);
380 if (!context) {
381 rc = -ENOMEM;
382 goto out_free;
383 }
384 if (!alloc)
385 alloc = 1;
386 seen |= Opt_context;
387 break;
388
389 case Opt_fscontext:
390 if (seen & (Opt_context|Opt_fscontext)) {
391 rc = -EINVAL;
392 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
393 goto out_free;
394 }
395 context = match_strdup(&args[0]);
396 if (!context) {
397 rc = -ENOMEM;
398 goto out_free;
399 }
400 if (!alloc)
401 alloc = 1;
402 seen |= Opt_fscontext;
403 break;
404
405 case Opt_defcontext:
406 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
407 rc = -EINVAL;
408 printk(KERN_WARNING "SELinux: "
409 "defcontext option is invalid "
410 "for this filesystem type\n");
411 goto out_free;
412 }
413 if (seen & (Opt_context|Opt_defcontext)) {
414 rc = -EINVAL;
415 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
416 goto out_free;
417 }
418 defcontext = match_strdup(&args[0]);
419 if (!defcontext) {
420 rc = -ENOMEM;
421 goto out_free;
422 }
423 if (!alloc)
424 alloc = 1;
425 seen |= Opt_defcontext;
426 break;
427
428 default:
429 rc = -EINVAL;
430 printk(KERN_WARNING "SELinux: unknown mount "
431 "option\n");
432 goto out_free;
433
434 }
435 }
436 }
437
438 if (!seen)
439 goto out;
440
441 if (context) {
442 rc = security_context_to_sid(context, strlen(context), &sid);
443 if (rc) {
444 printk(KERN_WARNING "SELinux: security_context_to_sid"
445 "(%s) failed for (dev %s, type %s) errno=%d\n",
446 context, sb->s_id, name, rc);
447 goto out_free;
448 }
449
450 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
451 FILESYSTEM__RELABELFROM, NULL);
452 if (rc)
453 goto out_free;
454
455 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
456 FILESYSTEM__RELABELTO, NULL);
457 if (rc)
458 goto out_free;
459
460 sbsec->sid = sid;
461
462 if (seen & Opt_context)
463 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
464 }
465
466 if (defcontext) {
467 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
468 if (rc) {
469 printk(KERN_WARNING "SELinux: security_context_to_sid"
470 "(%s) failed for (dev %s, type %s) errno=%d\n",
471 defcontext, sb->s_id, name, rc);
472 goto out_free;
473 }
474
475 if (sid == sbsec->def_sid)
476 goto out_free;
477
478 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
479 FILESYSTEM__RELABELFROM, NULL);
480 if (rc)
481 goto out_free;
482
483 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
484 FILESYSTEM__ASSOCIATE, NULL);
485 if (rc)
486 goto out_free;
487
488 sbsec->def_sid = sid;
489 }
490
491out_free:
492 if (alloc) {
493 kfree(context);
494 kfree(defcontext);
495 }
496out:
497 return rc;
498}
499
500static int superblock_doinit(struct super_block *sb, void *data)
501{
502 struct superblock_security_struct *sbsec = sb->s_security;
503 struct dentry *root = sb->s_root;
504 struct inode *inode = root->d_inode;
505 int rc = 0;
506
507 down(&sbsec->sem);
508 if (sbsec->initialized)
509 goto out;
510
511 if (!ss_initialized) {
512 /* Defer initialization until selinux_complete_init,
513 after the initial policy is loaded and the security
514 server is ready to handle calls. */
515 spin_lock(&sb_security_lock);
516 if (list_empty(&sbsec->list))
517 list_add(&sbsec->list, &superblock_security_head);
518 spin_unlock(&sb_security_lock);
519 goto out;
520 }
521
522 /* Determine the labeling behavior to use for this filesystem type. */
523 rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
524 if (rc) {
525 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
526 __FUNCTION__, sb->s_type->name, rc);
527 goto out;
528 }
529
530 rc = try_context_mount(sb, data);
531 if (rc)
532 goto out;
533
534 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
535 /* Make sure that the xattr handler exists and that no
536 error other than -ENODATA is returned by getxattr on
537 the root directory. -ENODATA is ok, as this may be
538 the first boot of the SELinux kernel before we have
539 assigned xattr values to the filesystem. */
540 if (!inode->i_op->getxattr) {
541 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
542 "xattr support\n", sb->s_id, sb->s_type->name);
543 rc = -EOPNOTSUPP;
544 goto out;
545 }
546 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
547 if (rc < 0 && rc != -ENODATA) {
548 if (rc == -EOPNOTSUPP)
549 printk(KERN_WARNING "SELinux: (dev %s, type "
550 "%s) has no security xattr handler\n",
551 sb->s_id, sb->s_type->name);
552 else
553 printk(KERN_WARNING "SELinux: (dev %s, type "
554 "%s) getxattr errno %d\n", sb->s_id,
555 sb->s_type->name, -rc);
556 goto out;
557 }
558 }
559
560 if (strcmp(sb->s_type->name, "proc") == 0)
561 sbsec->proc = 1;
562
563 sbsec->initialized = 1;
564
565 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
566 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
567 sb->s_id, sb->s_type->name);
568 }
569 else {
570 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
571 sb->s_id, sb->s_type->name,
572 labeling_behaviors[sbsec->behavior-1]);
573 }
574
575 /* Initialize the root inode. */
576 rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
577
578 /* Initialize any other inodes associated with the superblock, e.g.
579 inodes created prior to initial policy load or inodes created
580 during get_sb by a pseudo filesystem that directly
581 populates itself. */
582 spin_lock(&sbsec->isec_lock);
583next_inode:
584 if (!list_empty(&sbsec->isec_head)) {
585 struct inode_security_struct *isec =
586 list_entry(sbsec->isec_head.next,
587 struct inode_security_struct, list);
588 struct inode *inode = isec->inode;
589 spin_unlock(&sbsec->isec_lock);
590 inode = igrab(inode);
591 if (inode) {
592 if (!IS_PRIVATE (inode))
593 inode_doinit(inode);
594 iput(inode);
595 }
596 spin_lock(&sbsec->isec_lock);
597 list_del_init(&isec->list);
598 goto next_inode;
599 }
600 spin_unlock(&sbsec->isec_lock);
601out:
602 up(&sbsec->sem);
603 return rc;
604}
605
606static inline u16 inode_mode_to_security_class(umode_t mode)
607{
608 switch (mode & S_IFMT) {
609 case S_IFSOCK:
610 return SECCLASS_SOCK_FILE;
611 case S_IFLNK:
612 return SECCLASS_LNK_FILE;
613 case S_IFREG:
614 return SECCLASS_FILE;
615 case S_IFBLK:
616 return SECCLASS_BLK_FILE;
617 case S_IFDIR:
618 return SECCLASS_DIR;
619 case S_IFCHR:
620 return SECCLASS_CHR_FILE;
621 case S_IFIFO:
622 return SECCLASS_FIFO_FILE;
623
624 }
625
626 return SECCLASS_FILE;
627}
628
13402580
JM		 629static inline int default_protocol_stream(int protocol)
630{
631 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
632}
633
634static inline int default_protocol_dgram(int protocol)
635{
636 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
637}
638
1da177e4
LT		 639static inline u16 socket_type_to_security_class(int family, int type, int protocol)
640{
641 switch (family) {
642 case PF_UNIX:
643 switch (type) {
644 case SOCK_STREAM:
645 case SOCK_SEQPACKET:
646 return SECCLASS_UNIX_STREAM_SOCKET;
647 case SOCK_DGRAM:
648 return SECCLASS_UNIX_DGRAM_SOCKET;
649 }
650 break;
651 case PF_INET:
652 case PF_INET6:
653 switch (type) {
654 case SOCK_STREAM:
13402580
JM		 655 if (default_protocol_stream(protocol))
656 return SECCLASS_TCP_SOCKET;
657 else
658 return SECCLASS_RAWIP_SOCKET;
1da177e4 659 case SOCK_DGRAM:
13402580
JM		 660 if (default_protocol_dgram(protocol))
661 return SECCLASS_UDP_SOCKET;
662 else
663 return SECCLASS_RAWIP_SOCKET;
664 default:
1da177e4
LT		 665 return SECCLASS_RAWIP_SOCKET;
666 }
667 break;
668 case PF_NETLINK:
669 switch (protocol) {
670 case NETLINK_ROUTE:
671 return SECCLASS_NETLINK_ROUTE_SOCKET;
672 case NETLINK_FIREWALL:
673 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 674 case NETLINK_INET_DIAG:
1da177e4
LT		 675 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
676 case NETLINK_NFLOG:
677 return SECCLASS_NETLINK_NFLOG_SOCKET;
678 case NETLINK_XFRM:
679 return SECCLASS_NETLINK_XFRM_SOCKET;
680 case NETLINK_SELINUX:
681 return SECCLASS_NETLINK_SELINUX_SOCKET;
682 case NETLINK_AUDIT:
683 return SECCLASS_NETLINK_AUDIT_SOCKET;
684 case NETLINK_IP6_FW:
685 return SECCLASS_NETLINK_IP6FW_SOCKET;
686 case NETLINK_DNRTMSG:
687 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM		 688 case NETLINK_KOBJECT_UEVENT:
689 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT		 690 default:
691 return SECCLASS_NETLINK_SOCKET;
692 }
693 case PF_PACKET:
694 return SECCLASS_PACKET_SOCKET;
695 case PF_KEY:
696 return SECCLASS_KEY_SOCKET;
697 }
698
699 return SECCLASS_SOCKET;
700}
701
702#ifdef CONFIG_PROC_FS
703static int selinux_proc_get_sid(struct proc_dir_entry *de,
704 u16 tclass,
705 u32 *sid)
706{
707 int buflen, rc;
708 char *buffer, *path, *end;
709
710 buffer = (char*)__get_free_page(GFP_KERNEL);
711 if (!buffer)
712 return -ENOMEM;
713
714 buflen = PAGE_SIZE;
715 end = buffer+buflen;
716 *--end = '\0';
717 buflen--;
718 path = end-1;
719 *path = '/';
720 while (de && de != de->parent) {
721 buflen -= de->namelen + 1;
722 if (buflen < 0)
723 break;
724 end -= de->namelen;
725 memcpy(end, de->name, de->namelen);
726 *--end = '/';
727 path = end;
728 de = de->parent;
729 }
730 rc = security_genfs_sid("proc", path, tclass, sid);
731 free_page((unsigned long)buffer);
732 return rc;
733}
734#else
735static int selinux_proc_get_sid(struct proc_dir_entry *de,
736 u16 tclass,
737 u32 *sid)
738{
739 return -EINVAL;
740}
741#endif
742
743/* The inode's security attributes must be initialized before first use. */
744static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
745{
746 struct superblock_security_struct *sbsec = NULL;
747 struct inode_security_struct *isec = inode->i_security;
748 u32 sid;
749 struct dentry *dentry;
750#define INITCONTEXTLEN 255
751 char *context = NULL;
752 unsigned len = 0;
753 int rc = 0;
754 int hold_sem = 0;
755
756 if (isec->initialized)
757 goto out;
758
759 down(&isec->sem);
760 hold_sem = 1;
761 if (isec->initialized)
762 goto out;
763
764 sbsec = inode->i_sb->s_security;
765 if (!sbsec->initialized) {
766 /* Defer initialization until selinux_complete_init,
767 after the initial policy is loaded and the security
768 server is ready to handle calls. */
769 spin_lock(&sbsec->isec_lock);
770 if (list_empty(&isec->list))
771 list_add(&isec->list, &sbsec->isec_head);
772 spin_unlock(&sbsec->isec_lock);
773 goto out;
774 }
775
776 switch (sbsec->behavior) {
777 case SECURITY_FS_USE_XATTR:
778 if (!inode->i_op->getxattr) {
779 isec->sid = sbsec->def_sid;
780 break;
781 }
782
783 /* Need a dentry, since the xattr API requires one.
784 Life would be simpler if we could just pass the inode. */
785 if (opt_dentry) {
786 /* Called from d_instantiate or d_splice_alias. */
787 dentry = dget(opt_dentry);
788 } else {
789 /* Called from selinux_complete_init, try to find a dentry. */
790 dentry = d_find_alias(inode);
791 }
792 if (!dentry) {
793 printk(KERN_WARNING "%s: no dentry for dev=%s "
794 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
795 inode->i_ino);
796 goto out;
797 }
798
799 len = INITCONTEXTLEN;
800 context = kmalloc(len, GFP_KERNEL);
801 if (!context) {
802 rc = -ENOMEM;
803 dput(dentry);
804 goto out;
805 }
806 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
807 context, len);
808 if (rc == -ERANGE) {
809 /* Need a larger buffer. Query for the right size. */
810 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
811 NULL, 0);
812 if (rc < 0) {
813 dput(dentry);
814 goto out;
815 }
816 kfree(context);
817 len = rc;
818 context = kmalloc(len, GFP_KERNEL);
819 if (!context) {
820 rc = -ENOMEM;
821 dput(dentry);
822 goto out;
823 }
824 rc = inode->i_op->getxattr(dentry,
825 XATTR_NAME_SELINUX,
826 context, len);
827 }
828 dput(dentry);
829 if (rc < 0) {
830 if (rc != -ENODATA) {
831 printk(KERN_WARNING "%s: getxattr returned "
832 "%d for dev=%s ino=%ld\n", __FUNCTION__,
833 -rc, inode->i_sb->s_id, inode->i_ino);
834 kfree(context);
835 goto out;
836 }
837 /* Map ENODATA to the default file SID */
838 sid = sbsec->def_sid;
839 rc = 0;
840 } else {
f5c1d5b2
JM		 841 rc = security_context_to_sid_default(context, rc, &sid,
842 sbsec->def_sid);
1da177e4
LT		 843 if (rc) {
844 printk(KERN_WARNING "%s: context_to_sid(%s) "
845 "returned %d for dev=%s ino=%ld\n",
846 __FUNCTION__, context, -rc,
847 inode->i_sb->s_id, inode->i_ino);
848 kfree(context);
849 /* Leave with the unlabeled SID */
850 rc = 0;
851 break;
852 }
853 }
854 kfree(context);
855 isec->sid = sid;
856 break;
857 case SECURITY_FS_USE_TASK:
858 isec->sid = isec->task_sid;
859 break;
860 case SECURITY_FS_USE_TRANS:
861 /* Default to the fs SID. */
862 isec->sid = sbsec->sid;
863
864 /* Try to obtain a transition SID. */
865 isec->sclass = inode_mode_to_security_class(inode->i_mode);
866 rc = security_transition_sid(isec->task_sid,
867 sbsec->sid,
868 isec->sclass,
869 &sid);
870 if (rc)
871 goto out;
872 isec->sid = sid;
873 break;
874 default:
875 /* Default to the fs SID. */
876 isec->sid = sbsec->sid;
877
878 if (sbsec->proc) {
879 struct proc_inode *proci = PROC_I(inode);
880 if (proci->pde) {
881 isec->sclass = inode_mode_to_security_class(inode->i_mode);
882 rc = selinux_proc_get_sid(proci->pde,
883 isec->sclass,
884 &sid);
885 if (rc)
886 goto out;
887 isec->sid = sid;
888 }
889 }
890 break;
891 }
892
893 isec->initialized = 1;
894
895out:
896 if (isec->sclass == SECCLASS_FILE)
897 isec->sclass = inode_mode_to_security_class(inode->i_mode);
898
899 if (hold_sem)
900 up(&isec->sem);
901 return rc;
902}
903
904/* Convert a Linux signal to an access vector. */
905static inline u32 signal_to_av(int sig)
906{
907 u32 perm = 0;
908
909 switch (sig) {
910 case SIGCHLD:
911 /* Commonly granted from child to parent. */
912 perm = PROCESS__SIGCHLD;
913 break;
914 case SIGKILL:
915 /* Cannot be caught or ignored */
916 perm = PROCESS__SIGKILL;
917 break;
918 case SIGSTOP:
919 /* Cannot be caught or ignored */
920 perm = PROCESS__SIGSTOP;
921 break;
922 default:
923 /* All other signals. */
924 perm = PROCESS__SIGNAL;
925 break;
926 }
927
928 return perm;
929}
930
931/* Check permission betweeen a pair of tasks, e.g. signal checks,
932 fork check, ptrace check, etc. */
933static int task_has_perm(struct task_struct *tsk1,
934 struct task_struct *tsk2,
935 u32 perms)
936{
937 struct task_security_struct *tsec1, *tsec2;
938
939 tsec1 = tsk1->security;
940 tsec2 = tsk2->security;
941 return avc_has_perm(tsec1->sid, tsec2->sid,
942 SECCLASS_PROCESS, perms, NULL);
943}
944
945/* Check whether a task is allowed to use a capability. */
946static int task_has_capability(struct task_struct *tsk,
947 int cap)
948{
949 struct task_security_struct *tsec;
950 struct avc_audit_data ad;
951
952 tsec = tsk->security;
953
954 AVC_AUDIT_DATA_INIT(&ad,CAP);
955 ad.tsk = tsk;
956 ad.u.cap = cap;
957
958 return avc_has_perm(tsec->sid, tsec->sid,
959 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
960}
961
962/* Check whether a task is allowed to use a system operation. */
963static int task_has_system(struct task_struct *tsk,
964 u32 perms)
965{
966 struct task_security_struct *tsec;
967
968 tsec = tsk->security;
969
970 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
971 SECCLASS_SYSTEM, perms, NULL);
972}
973
974/* Check whether a task has a particular permission to an inode.
975 The 'adp' parameter is optional and allows other audit
976 data to be passed (e.g. the dentry). */
977static int inode_has_perm(struct task_struct *tsk,
978 struct inode *inode,
979 u32 perms,
980 struct avc_audit_data *adp)
981{
982 struct task_security_struct *tsec;
983 struct inode_security_struct *isec;
984 struct avc_audit_data ad;
985
986 tsec = tsk->security;
987 isec = inode->i_security;
988
989 if (!adp) {
990 adp = &ad;
991 AVC_AUDIT_DATA_INIT(&ad, FS);
992 ad.u.fs.inode = inode;
993 }
994
995 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
996}
997
998/* Same as inode_has_perm, but pass explicit audit data containing
999 the dentry to help the auditing code to more easily generate the
1000 pathname if needed. */
1001static inline int dentry_has_perm(struct task_struct *tsk,
1002 struct vfsmount *mnt,
1003 struct dentry *dentry,
1004 u32 av)
1005{
1006 struct inode *inode = dentry->d_inode;
1007 struct avc_audit_data ad;
1008 AVC_AUDIT_DATA_INIT(&ad,FS);
1009 ad.u.fs.mnt = mnt;
1010 ad.u.fs.dentry = dentry;
1011 return inode_has_perm(tsk, inode, av, &ad);
1012}
1013
1014/* Check whether a task can use an open file descriptor to
1015 access an inode in a given way. Check access to the
1016 descriptor itself, and then use dentry_has_perm to
1017 check a particular permission to the file.
1018 Access to the descriptor is implicitly granted if it
1019 has the same SID as the process. If av is zero, then
1020 access to the file is not checked, e.g. for cases
1021 where only the descriptor is affected like seek. */
858119e1 1022static int file_has_perm(struct task_struct *tsk,
1da177e4
LT		 1023 struct file *file,
1024 u32 av)
1025{
1026 struct task_security_struct *tsec = tsk->security;
1027 struct file_security_struct *fsec = file->f_security;
1028 struct vfsmount *mnt = file->f_vfsmnt;
1029 struct dentry *dentry = file->f_dentry;
1030 struct inode *inode = dentry->d_inode;
1031 struct avc_audit_data ad;
1032 int rc;
1033
1034 AVC_AUDIT_DATA_INIT(&ad, FS);
1035 ad.u.fs.mnt = mnt;
1036 ad.u.fs.dentry = dentry;
1037
1038 if (tsec->sid != fsec->sid) {
1039 rc = avc_has_perm(tsec->sid, fsec->sid,
1040 SECCLASS_FD,
1041 FD__USE,
1042 &ad);
1043 if (rc)
1044 return rc;
1045 }
1046
1047 /* av is zero if only checking access to the descriptor. */
1048 if (av)
1049 return inode_has_perm(tsk, inode, av, &ad);
1050
1051 return 0;
1052}
1053
1054/* Check whether a task can create a file. */
1055static int may_create(struct inode *dir,
1056 struct dentry *dentry,
1057 u16 tclass)
1058{
1059 struct task_security_struct *tsec;
1060 struct inode_security_struct *dsec;
1061 struct superblock_security_struct *sbsec;
1062 u32 newsid;
1063 struct avc_audit_data ad;
1064 int rc;
1065
1066 tsec = current->security;
1067 dsec = dir->i_security;
1068 sbsec = dir->i_sb->s_security;
1069
1070 AVC_AUDIT_DATA_INIT(&ad, FS);
1071 ad.u.fs.dentry = dentry;
1072
1073 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1074 DIR__ADD_NAME | DIR__SEARCH,
1075 &ad);
1076 if (rc)
1077 return rc;
1078
1079 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1080 newsid = tsec->create_sid;
1081 } else {
1082 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1083 &newsid);
1084 if (rc)
1085 return rc;
1086 }
1087
1088 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1089 if (rc)
1090 return rc;
1091
1092 return avc_has_perm(newsid, sbsec->sid,
1093 SECCLASS_FILESYSTEM,
1094 FILESYSTEM__ASSOCIATE, &ad);
1095}
1096
1097#define MAY_LINK 0
1098#define MAY_UNLINK 1
1099#define MAY_RMDIR 2
1100
1101/* Check whether a task can link, unlink, or rmdir a file/directory. */
1102static int may_link(struct inode *dir,
1103 struct dentry *dentry,
1104 int kind)
1105
1106{
1107 struct task_security_struct *tsec;
1108 struct inode_security_struct *dsec, *isec;
1109 struct avc_audit_data ad;
1110 u32 av;
1111 int rc;
1112
1113 tsec = current->security;
1114 dsec = dir->i_security;
1115 isec = dentry->d_inode->i_security;
1116
1117 AVC_AUDIT_DATA_INIT(&ad, FS);
1118 ad.u.fs.dentry = dentry;
1119
1120 av = DIR__SEARCH;
1121 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1122 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1123 if (rc)
1124 return rc;
1125
1126 switch (kind) {
1127 case MAY_LINK:
1128 av = FILE__LINK;
1129 break;
1130 case MAY_UNLINK:
1131 av = FILE__UNLINK;
1132 break;
1133 case MAY_RMDIR:
1134 av = DIR__RMDIR;
1135 break;
1136 default:
1137 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1138 return 0;
1139 }
1140
1141 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1142 return rc;
1143}
1144
1145static inline int may_rename(struct inode *old_dir,
1146 struct dentry *old_dentry,
1147 struct inode *new_dir,
1148 struct dentry *new_dentry)
1149{
1150 struct task_security_struct *tsec;
1151 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1152 struct avc_audit_data ad;
1153 u32 av;
1154 int old_is_dir, new_is_dir;
1155 int rc;
1156
1157 tsec = current->security;
1158 old_dsec = old_dir->i_security;
1159 old_isec = old_dentry->d_inode->i_security;
1160 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1161 new_dsec = new_dir->i_security;
1162
1163 AVC_AUDIT_DATA_INIT(&ad, FS);
1164
1165 ad.u.fs.dentry = old_dentry;
1166 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1167 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1168 if (rc)
1169 return rc;
1170 rc = avc_has_perm(tsec->sid, old_isec->sid,
1171 old_isec->sclass, FILE__RENAME, &ad);
1172 if (rc)
1173 return rc;
1174 if (old_is_dir && new_dir != old_dir) {
1175 rc = avc_has_perm(tsec->sid, old_isec->sid,
1176 old_isec->sclass, DIR__REPARENT, &ad);
1177 if (rc)
1178 return rc;
1179 }
1180
1181 ad.u.fs.dentry = new_dentry;
1182 av = DIR__ADD_NAME | DIR__SEARCH;
1183 if (new_dentry->d_inode)
1184 av |= DIR__REMOVE_NAME;
1185 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1186 if (rc)
1187 return rc;
1188 if (new_dentry->d_inode) {
1189 new_isec = new_dentry->d_inode->i_security;
1190 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1191 rc = avc_has_perm(tsec->sid, new_isec->sid,
1192 new_isec->sclass,
1193 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1194 if (rc)
1195 return rc;
1196 }
1197
1198 return 0;
1199}
1200
1201/* Check whether a task can perform a filesystem operation. */
1202static int superblock_has_perm(struct task_struct *tsk,
1203 struct super_block *sb,
1204 u32 perms,
1205 struct avc_audit_data *ad)
1206{
1207 struct task_security_struct *tsec;
1208 struct superblock_security_struct *sbsec;
1209
1210 tsec = tsk->security;
1211 sbsec = sb->s_security;
1212 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1213 perms, ad);
1214}
1215
1216/* Convert a Linux mode and permission mask to an access vector. */
1217static inline u32 file_mask_to_av(int mode, int mask)
1218{
1219 u32 av = 0;
1220
1221 if ((mode & S_IFMT) != S_IFDIR) {
1222 if (mask & MAY_EXEC)
1223 av |= FILE__EXECUTE;
1224 if (mask & MAY_READ)
1225 av |= FILE__READ;
1226
1227 if (mask & MAY_APPEND)
1228 av |= FILE__APPEND;
1229 else if (mask & MAY_WRITE)
1230 av |= FILE__WRITE;
1231
1232 } else {
1233 if (mask & MAY_EXEC)
1234 av |= DIR__SEARCH;
1235 if (mask & MAY_WRITE)
1236 av |= DIR__WRITE;
1237 if (mask & MAY_READ)
1238 av |= DIR__READ;
1239 }
1240
1241 return av;
1242}
1243
1244/* Convert a Linux file to an access vector. */
1245static inline u32 file_to_av(struct file *file)
1246{
1247 u32 av = 0;
1248
1249 if (file->f_mode & FMODE_READ)
1250 av |= FILE__READ;
1251 if (file->f_mode & FMODE_WRITE) {
1252 if (file->f_flags & O_APPEND)
1253 av |= FILE__APPEND;
1254 else
1255 av |= FILE__WRITE;
1256 }
1257
1258 return av;
1259}
1260
1261/* Set an inode's SID to a specified value. */
1262static int inode_security_set_sid(struct inode *inode, u32 sid)
1263{
1264 struct inode_security_struct *isec = inode->i_security;
1265 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
1266
1267 if (!sbsec->initialized) {
1268 /* Defer initialization to selinux_complete_init. */
1269 return 0;
1270 }
1271
1272 down(&isec->sem);
1273 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1274 isec->sid = sid;
1275 isec->initialized = 1;
1276 up(&isec->sem);
1277 return 0;
1278}
1279
1da177e4
LT		 1280/* Hook functions begin here. */
1281
1282static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1283{
1284 struct task_security_struct *psec = parent->security;
1285 struct task_security_struct *csec = child->security;
1286 int rc;
1287
1288 rc = secondary_ops->ptrace(parent,child);
1289 if (rc)
1290 return rc;
1291
1292 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1293 /* Save the SID of the tracing process for later use in apply_creds. */
1294 if (!rc)
1295 csec->ptrace_sid = psec->sid;
1296 return rc;
1297}
1298
1299static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1300 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1301{
1302 int error;
1303
1304 error = task_has_perm(current, target, PROCESS__GETCAP);
1305 if (error)
1306 return error;
1307
1308 return secondary_ops->capget(target, effective, inheritable, permitted);
1309}
1310
1311static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1312 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1313{
1314 int error;
1315
1316 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1317 if (error)
1318 return error;
1319
1320 return task_has_perm(current, target, PROCESS__SETCAP);
1321}
1322
1323static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1324 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1325{
1326 secondary_ops->capset_set(target, effective, inheritable, permitted);
1327}
1328
1329static int selinux_capable(struct task_struct *tsk, int cap)
1330{
1331 int rc;
1332
1333 rc = secondary_ops->capable(tsk, cap);
1334 if (rc)
1335 return rc;
1336
1337 return task_has_capability(tsk,cap);
1338}
1339
1340static int selinux_sysctl(ctl_table *table, int op)
1341{
1342 int error = 0;
1343 u32 av;
1344 struct task_security_struct *tsec;
1345 u32 tsid;
1346 int rc;
1347
1348 rc = secondary_ops->sysctl(table, op);
1349 if (rc)
1350 return rc;
1351
1352 tsec = current->security;
1353
1354 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1355 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1356 if (rc) {
1357 /* Default to the well-defined sysctl SID. */
1358 tsid = SECINITSID_SYSCTL;
1359 }
1360
1361 /* The op values are "defined" in sysctl.c, thereby creating
1362 * a bad coupling between this module and sysctl.c */
1363 if(op == 001) {
1364 error = avc_has_perm(tsec->sid, tsid,
1365 SECCLASS_DIR, DIR__SEARCH, NULL);
1366 } else {
1367 av = 0;
1368 if (op & 004)
1369 av |= FILE__READ;
1370 if (op & 002)
1371 av |= FILE__WRITE;
1372 if (av)
1373 error = avc_has_perm(tsec->sid, tsid,
1374 SECCLASS_FILE, av, NULL);
1375 }
1376
1377 return error;
1378}
1379
1380static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1381{
1382 int rc = 0;
1383
1384 if (!sb)
1385 return 0;
1386
1387 switch (cmds) {
1388 case Q_SYNC:
1389 case Q_QUOTAON:
1390 case Q_QUOTAOFF:
1391 case Q_SETINFO:
1392 case Q_SETQUOTA:
1393 rc = superblock_has_perm(current,
1394 sb,
1395 FILESYSTEM__QUOTAMOD, NULL);
1396 break;
1397 case Q_GETFMT:
1398 case Q_GETINFO:
1399 case Q_GETQUOTA:
1400 rc = superblock_has_perm(current,
1401 sb,
1402 FILESYSTEM__QUOTAGET, NULL);
1403 break;
1404 default:
1405 rc = 0; /* let the kernel handle invalid cmds */
1406 break;
1407 }
1408 return rc;
1409}
1410
1411static int selinux_quota_on(struct dentry *dentry)
1412{
1413 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1414}
1415
1416static int selinux_syslog(int type)
1417{
1418 int rc;
1419
1420 rc = secondary_ops->syslog(type);
1421 if (rc)
1422 return rc;
1423
1424 switch (type) {
1425 case 3: /* Read last kernel messages */
1426 case 10: /* Return size of the log buffer */
1427 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1428 break;
1429 case 6: /* Disable logging to console */
1430 case 7: /* Enable logging to console */
1431 case 8: /* Set level of messages printed to console */
1432 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1433 break;
1434 case 0: /* Close log */
1435 case 1: /* Open log */
1436 case 2: /* Read from log */
1437 case 4: /* Read/clear last kernel messages */
1438 case 5: /* Clear ring buffer */
1439 default:
1440 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1441 break;
1442 }
1443 return rc;
1444}
1445
1446/*
1447 * Check that a process has enough memory to allocate a new virtual
1448 * mapping. 0 means there is enough memory for the allocation to
1449 * succeed and -ENOMEM implies there is not.
1450 *
1451 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1452 * if the capability is granted, but __vm_enough_memory requires 1 if
1453 * the capability is granted.
1454 *
1455 * Do not audit the selinux permission check, as this is applied to all
1456 * processes that allocate mappings.
1457 */
1458static int selinux_vm_enough_memory(long pages)
1459{
1460 int rc, cap_sys_admin = 0;
1461 struct task_security_struct *tsec = current->security;
1462
1463 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1464 if (rc == 0)
1465 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1466 SECCLASS_CAPABILITY,
1467 CAP_TO_MASK(CAP_SYS_ADMIN),
1468 NULL);
1469
1470 if (rc == 0)
1471 cap_sys_admin = 1;
1472
1473 return __vm_enough_memory(pages, cap_sys_admin);
1474}
1475
1476/* binprm security operations */
1477
1478static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1479{
1480 struct bprm_security_struct *bsec;
1481
89d155ef 1482 bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1da177e4
LT		 1483 if (!bsec)
1484 return -ENOMEM;
1485
1da177e4
LT		 1486 bsec->magic = SELINUX_MAGIC;
1487 bsec->bprm = bprm;
1488 bsec->sid = SECINITSID_UNLABELED;
1489 bsec->set = 0;
1490
1491 bprm->security = bsec;
1492 return 0;
1493}
1494
1495static int selinux_bprm_set_security(struct linux_binprm *bprm)
1496{
1497 struct task_security_struct *tsec;
1498 struct inode *inode = bprm->file->f_dentry->d_inode;
1499 struct inode_security_struct *isec;
1500 struct bprm_security_struct *bsec;
1501 u32 newsid;
1502 struct avc_audit_data ad;
1503 int rc;
1504
1505 rc = secondary_ops->bprm_set_security(bprm);
1506 if (rc)
1507 return rc;
1508
1509 bsec = bprm->security;
1510
1511 if (bsec->set)
1512 return 0;
1513
1514 tsec = current->security;
1515 isec = inode->i_security;
1516
1517 /* Default to the current task SID. */
1518 bsec->sid = tsec->sid;
1519
1520 /* Reset create SID on execve. */
1521 tsec->create_sid = 0;
1522
1523 if (tsec->exec_sid) {
1524 newsid = tsec->exec_sid;
1525 /* Reset exec SID on execve. */
1526 tsec->exec_sid = 0;
1527 } else {
1528 /* Check for a default transition on this program. */
1529 rc = security_transition_sid(tsec->sid, isec->sid,
1530 SECCLASS_PROCESS, &newsid);
1531 if (rc)
1532 return rc;
1533 }
1534
1535 AVC_AUDIT_DATA_INIT(&ad, FS);
1536 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1537 ad.u.fs.dentry = bprm->file->f_dentry;
1538
1539 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1540 newsid = tsec->sid;
1541
1542 if (tsec->sid == newsid) {
1543 rc = avc_has_perm(tsec->sid, isec->sid,
1544 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1545 if (rc)
1546 return rc;
1547 } else {
1548 /* Check permissions for the transition. */
1549 rc = avc_has_perm(tsec->sid, newsid,
1550 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1551 if (rc)
1552 return rc;
1553
1554 rc = avc_has_perm(newsid, isec->sid,
1555 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1556 if (rc)
1557 return rc;
1558
1559 /* Clear any possibly unsafe personality bits on exec: */
1560 current->personality &= ~PER_CLEAR_ON_SETID;
1561
1562 /* Set the security field to the new SID. */
1563 bsec->sid = newsid;
1564 }
1565
1566 bsec->set = 1;
1567 return 0;
1568}
1569
1570static int selinux_bprm_check_security (struct linux_binprm *bprm)
1571{
1572 return secondary_ops->bprm_check_security(bprm);
1573}
1574
1575
1576static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1577{
1578 struct task_security_struct *tsec = current->security;
1579 int atsecure = 0;
1580
1581 if (tsec->osid != tsec->sid) {
1582 /* Enable secure mode for SIDs transitions unless
1583 the noatsecure permission is granted between
1584 the two SIDs, i.e. ahp returns 0. */
1585 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1586 SECCLASS_PROCESS,
1587 PROCESS__NOATSECURE, NULL);
1588 }
1589
1590 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1591}
1592
1593static void selinux_bprm_free_security(struct linux_binprm *bprm)
1594{
9a5f04bf 1595 kfree(bprm->security);
1da177e4 1596 bprm->security = NULL;
1da177e4
LT		 1597}
1598
1599extern struct vfsmount *selinuxfs_mount;
1600extern struct dentry *selinux_null;
1601
1602/* Derived from fs/exec.c:flush_old_files. */
1603static inline void flush_unauthorized_files(struct files_struct * files)
1604{
1605 struct avc_audit_data ad;
1606 struct file *file, *devnull = NULL;
1607 struct tty_struct *tty = current->signal->tty;
badf1662 1608 struct fdtable *fdt;
1da177e4
LT		 1609 long j = -1;
1610
1611 if (tty) {
1612 file_list_lock();
2f512016 1613 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1614 if (file) {
1615 /* Revalidate access to controlling tty.
1616 Use inode_has_perm on the tty inode directly rather
1617 than using file_has_perm, as this particular open
1618 file may belong to another process and we are only
1619 interested in the inode-based check here. */
1620 struct inode *inode = file->f_dentry->d_inode;
1621 if (inode_has_perm(current, inode,
1622 FILE__READ | FILE__WRITE, NULL)) {
1623 /* Reset controlling tty. */
1624 current->signal->tty = NULL;
1625 current->signal->tty_old_pgrp = 0;
1626 }
1627 }
1628 file_list_unlock();
1629 }
1630
1631 /* Revalidate access to inherited open files. */
1632
1633 AVC_AUDIT_DATA_INIT(&ad,FS);
1634
1635 spin_lock(&files->file_lock);
1636 for (;;) {
1637 unsigned long set, i;
1638 int fd;
1639
1640 j++;
1641 i = j * __NFDBITS;
badf1662
DS		 1642 fdt = files_fdtable(files);
1643 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1da177e4 1644 break;
badf1662 1645 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1646 if (!set)
1647 continue;
1648 spin_unlock(&files->file_lock);
1649 for ( ; set ; i++,set >>= 1) {
1650 if (set & 1) {
1651 file = fget(i);
1652 if (!file)
1653 continue;
1654 if (file_has_perm(current,
1655 file,
1656 file_to_av(file))) {
1657 sys_close(i);
1658 fd = get_unused_fd();
1659 if (fd != i) {
1660 if (fd >= 0)
1661 put_unused_fd(fd);
1662 fput(file);
1663 continue;
1664 }
1665 if (devnull) {
095975da 1666 get_file(devnull);
1da177e4
LT		 1667 } else {
1668 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1669 if (!devnull) {
1670 put_unused_fd(fd);
1671 fput(file);
1672 continue;
1673 }
1674 }
1675 fd_install(fd, devnull);
1676 }
1677 fput(file);
1678 }
1679 }
1680 spin_lock(&files->file_lock);
1681
1682 }
1683 spin_unlock(&files->file_lock);
1684}
1685
1686static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1687{
1688 struct task_security_struct *tsec;
1689 struct bprm_security_struct *bsec;
1690 u32 sid;
1691 int rc;
1692
1693 secondary_ops->bprm_apply_creds(bprm, unsafe);
1694
1695 tsec = current->security;
1696
1697 bsec = bprm->security;
1698 sid = bsec->sid;
1699
1700 tsec->osid = tsec->sid;
1701 bsec->unsafe = 0;
1702 if (tsec->sid != sid) {
1703 /* Check for shared state. If not ok, leave SID
1704 unchanged and kill. */
1705 if (unsafe & LSM_UNSAFE_SHARE) {
1706 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1707 PROCESS__SHARE, NULL);
1708 if (rc) {
1709 bsec->unsafe = 1;
1710 return;
1711 }
1712 }
1713
1714 /* Check for ptracing, and update the task SID if ok.
1715 Otherwise, leave SID unchanged and kill. */
1716 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1717 rc = avc_has_perm(tsec->ptrace_sid, sid,
1718 SECCLASS_PROCESS, PROCESS__PTRACE,
1719 NULL);
1720 if (rc) {
1721 bsec->unsafe = 1;
1722 return;
1723 }
1724 }
1725 tsec->sid = sid;
1726 }
1727}
1728
1729/*
1730 * called after apply_creds without the task lock held
1731 */
1732static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1733{
1734 struct task_security_struct *tsec;
1735 struct rlimit *rlim, *initrlim;
1736 struct itimerval itimer;
1737 struct bprm_security_struct *bsec;
1738 int rc, i;
1739
1740 tsec = current->security;
1741 bsec = bprm->security;
1742
1743 if (bsec->unsafe) {
1744 force_sig_specific(SIGKILL, current);
1745 return;
1746 }
1747 if (tsec->osid == tsec->sid)
1748 return;
1749
1750 /* Close files for which the new task SID is not authorized. */
1751 flush_unauthorized_files(current->files);
1752
1753 /* Check whether the new SID can inherit signal state
1754 from the old SID. If not, clear itimers to avoid
1755 subsequent signal generation and flush and unblock
1756 signals. This must occur _after_ the task SID has
1757 been updated so that any kill done after the flush
1758 will be checked against the new SID. */
1759 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1760 PROCESS__SIGINH, NULL);
1761 if (rc) {
1762 memset(&itimer, 0, sizeof itimer);
1763 for (i = 0; i < 3; i++)
1764 do_setitimer(i, &itimer, NULL);
1765 flush_signals(current);
1766 spin_lock_irq(&current->sighand->siglock);
1767 flush_signal_handlers(current, 1);
1768 sigemptyset(&current->blocked);
1769 recalc_sigpending();
1770 spin_unlock_irq(&current->sighand->siglock);
1771 }
1772
1773 /* Check whether the new SID can inherit resource limits
1774 from the old SID. If not, reset all soft limits to
1775 the lower of the current task's hard limit and the init
1776 task's soft limit. Note that the setting of hard limits
1777 (even to lower them) can be controlled by the setrlimit
1778 check. The inclusion of the init task's soft limit into
1779 the computation is to avoid resetting soft limits higher
1780 than the default soft limit for cases where the default
1781 is lower than the hard limit, e.g. RLIMIT_CORE or
1782 RLIMIT_STACK.*/
1783 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1784 PROCESS__RLIMITINH, NULL);
1785 if (rc) {
1786 for (i = 0; i < RLIM_NLIMITS; i++) {
1787 rlim = current->signal->rlim + i;
1788 initrlim = init_task.signal->rlim+i;
1789 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1790 }
1791 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1792 /*
1793 * This will cause RLIMIT_CPU calculations
1794 * to be refigured.
1795 */
1796 current->it_prof_expires = jiffies_to_cputime(1);
1797 }
1798 }
1799
1800 /* Wake up the parent if it is waiting so that it can
1801 recheck wait permission to the new task SID. */
1802 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1803}
1804
1805/* superblock security operations */
1806
1807static int selinux_sb_alloc_security(struct super_block *sb)
1808{
1809 return superblock_alloc_security(sb);
1810}
1811
1812static void selinux_sb_free_security(struct super_block *sb)
1813{
1814 superblock_free_security(sb);
1815}
1816
1817static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1818{
1819 if (plen > olen)
1820 return 0;
1821
1822 return !memcmp(prefix, option, plen);
1823}
1824
1825static inline int selinux_option(char *option, int len)
1826{
1827 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1828 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1829 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1830}
1831
1832static inline void take_option(char **to, char *from, int *first, int len)
1833{
1834 if (!*first) {
1835 **to = ',';
1836 *to += 1;
1837 }
1838 else
1839 *first = 0;
1840 memcpy(*to, from, len);
1841 *to += len;
1842}
1843
1844static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1845{
1846 int fnosec, fsec, rc = 0;
1847 char *in_save, *in_curr, *in_end;
1848 char *sec_curr, *nosec_save, *nosec;
1849
1850 in_curr = orig;
1851 sec_curr = copy;
1852
1853 /* Binary mount data: just copy */
1854 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1855 copy_page(sec_curr, in_curr);
1856 goto out;
1857 }
1858
1859 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1860 if (!nosec) {
1861 rc = -ENOMEM;
1862 goto out;
1863 }
1864
1865 nosec_save = nosec;
1866 fnosec = fsec = 1;
1867 in_save = in_end = orig;
1868
1869 do {
1870 if (*in_end == ',' || *in_end == '\0') {
1871 int len = in_end - in_curr;
1872
1873 if (selinux_option(in_curr, len))
1874 take_option(&sec_curr, in_curr, &fsec, len);
1875 else
1876 take_option(&nosec, in_curr, &fnosec, len);
1877
1878 in_curr = in_end + 1;
1879 }
1880 } while (*in_end++);
1881
6931dfc9 1882 strcpy(in_save, nosec_save);
da3caa20 1883 free_page((unsigned long)nosec_save);
1da177e4
LT		 1884out:
1885 return rc;
1886}
1887
1888static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1889{
1890 struct avc_audit_data ad;
1891 int rc;
1892
1893 rc = superblock_doinit(sb, data);
1894 if (rc)
1895 return rc;
1896
1897 AVC_AUDIT_DATA_INIT(&ad,FS);
1898 ad.u.fs.dentry = sb->s_root;
1899 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1900}
1901
1902static int selinux_sb_statfs(struct super_block *sb)
1903{
1904 struct avc_audit_data ad;
1905
1906 AVC_AUDIT_DATA_INIT(&ad,FS);
1907 ad.u.fs.dentry = sb->s_root;
1908 return superblock_has_perm(current, sb, FILESYSTEM__GETATTR, &ad);
1909}
1910
1911static int selinux_mount(char * dev_name,
1912 struct nameidata *nd,
1913 char * type,
1914 unsigned long flags,
1915 void * data)
1916{
1917 int rc;
1918
1919 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1920 if (rc)
1921 return rc;
1922
1923 if (flags & MS_REMOUNT)
1924 return superblock_has_perm(current, nd->mnt->mnt_sb,
1925 FILESYSTEM__REMOUNT, NULL);
1926 else
1927 return dentry_has_perm(current, nd->mnt, nd->dentry,
1928 FILE__MOUNTON);
1929}
1930
1931static int selinux_umount(struct vfsmount *mnt, int flags)
1932{
1933 int rc;
1934
1935 rc = secondary_ops->sb_umount(mnt, flags);
1936 if (rc)
1937 return rc;
1938
1939 return superblock_has_perm(current,mnt->mnt_sb,
1940 FILESYSTEM__UNMOUNT,NULL);
1941}
1942
1943/* inode security operations */
1944
1945static int selinux_inode_alloc_security(struct inode *inode)
1946{
1947 return inode_alloc_security(inode);
1948}
1949
1950static void selinux_inode_free_security(struct inode *inode)
1951{
1952 inode_free_security(inode);
1953}
1954
5e41ff9e
SS		 1955static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
1956 char **name, void **value,
1957 size_t *len)
1958{
1959 struct task_security_struct *tsec;
1960 struct inode_security_struct *dsec;
1961 struct superblock_security_struct *sbsec;
1962 struct inode_security_struct *isec;
570bc1c2 1963 u32 newsid, clen;
5e41ff9e 1964 int rc;
570bc1c2 1965 char *namep = NULL, *context;
5e41ff9e
SS		 1966
1967 tsec = current->security;
1968 dsec = dir->i_security;
1969 sbsec = dir->i_sb->s_security;
1970 isec = inode->i_security;
1971
1972 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1973 newsid = tsec->create_sid;
1974 } else {
1975 rc = security_transition_sid(tsec->sid, dsec->sid,
1976 inode_mode_to_security_class(inode->i_mode),
1977 &newsid);
1978 if (rc) {
1979 printk(KERN_WARNING "%s: "
1980 "security_transition_sid failed, rc=%d (dev=%s "
1981 "ino=%ld)\n",
1982 __FUNCTION__,
1983 -rc, inode->i_sb->s_id, inode->i_ino);
1984 return rc;
1985 }
1986 }
1987
1988 inode_security_set_sid(inode, newsid);
1989
25a74f3b
SS		 1990 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
1991 return -EOPNOTSUPP;
1992
570bc1c2
SS		 1993 if (name) {
1994 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
1995 if (!namep)
1996 return -ENOMEM;
1997 *name = namep;
1998 }
5e41ff9e 1999
570bc1c2
SS		 2000 if (value && len) {
2001 rc = security_sid_to_context(newsid, &context, &clen);
2002 if (rc) {
2003 kfree(namep);
2004 return rc;
2005 }
2006 *value = context;
2007 *len = clen;
5e41ff9e 2008 }
5e41ff9e 2009
5e41ff9e
SS		 2010 return 0;
2011}
2012
1da177e4
LT		 2013static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2014{
2015 return may_create(dir, dentry, SECCLASS_FILE);
2016}
2017
1da177e4
LT		 2018static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2019{
2020 int rc;
2021
2022 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2023 if (rc)
2024 return rc;
2025 return may_link(dir, old_dentry, MAY_LINK);
2026}
2027
1da177e4
LT		 2028static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2029{
2030 int rc;
2031
2032 rc = secondary_ops->inode_unlink(dir, dentry);
2033 if (rc)
2034 return rc;
2035 return may_link(dir, dentry, MAY_UNLINK);
2036}
2037
2038static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2039{
2040 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2041}
2042
1da177e4
LT		 2043static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2044{
2045 return may_create(dir, dentry, SECCLASS_DIR);
2046}
2047
1da177e4
LT		 2048static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2049{
2050 return may_link(dir, dentry, MAY_RMDIR);
2051}
2052
2053static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2054{
2055 int rc;
2056
2057 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2058 if (rc)
2059 return rc;
2060
2061 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2062}
2063
1da177e4
LT		 2064static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2065 struct inode *new_inode, struct dentry *new_dentry)
2066{
2067 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2068}
2069
1da177e4
LT		 2070static int selinux_inode_readlink(struct dentry *dentry)
2071{
2072 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2073}
2074
2075static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2076{
2077 int rc;
2078
2079 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2080 if (rc)
2081 return rc;
2082 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2083}
2084
2085static int selinux_inode_permission(struct inode *inode, int mask,
2086 struct nameidata *nd)
2087{
2088 int rc;
2089
2090 rc = secondary_ops->inode_permission(inode, mask, nd);
2091 if (rc)
2092 return rc;
2093
2094 if (!mask) {
2095 /* No permission to check. Existence test. */
2096 return 0;
2097 }
2098
2099 return inode_has_perm(current, inode,
2100 file_mask_to_av(inode->i_mode, mask), NULL);
2101}
2102
2103static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2104{
2105 int rc;
2106
2107 rc = secondary_ops->inode_setattr(dentry, iattr);
2108 if (rc)
2109 return rc;
2110
2111 if (iattr->ia_valid & ATTR_FORCE)
2112 return 0;
2113
2114 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2115 ATTR_ATIME_SET | ATTR_MTIME_SET))
2116 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2117
2118 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2119}
2120
2121static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2122{
2123 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2124}
2125
2126static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2127{
2128 struct task_security_struct *tsec = current->security;
2129 struct inode *inode = dentry->d_inode;
2130 struct inode_security_struct *isec = inode->i_security;
2131 struct superblock_security_struct *sbsec;
2132 struct avc_audit_data ad;
2133 u32 newsid;
2134 int rc = 0;
2135
2136 if (strcmp(name, XATTR_NAME_SELINUX)) {
2137 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2138 sizeof XATTR_SECURITY_PREFIX - 1) &&
2139 !capable(CAP_SYS_ADMIN)) {
2140 /* A different attribute in the security namespace.
2141 Restrict to administrator. */
2142 return -EPERM;
2143 }
2144
2145 /* Not an attribute we recognize, so just check the
2146 ordinary setattr permission. */
2147 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2148 }
2149
2150 sbsec = inode->i_sb->s_security;
2151 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2152 return -EOPNOTSUPP;
2153
2154 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2155 return -EPERM;
2156
2157 AVC_AUDIT_DATA_INIT(&ad,FS);
2158 ad.u.fs.dentry = dentry;
2159
2160 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2161 FILE__RELABELFROM, &ad);
2162 if (rc)
2163 return rc;
2164
2165 rc = security_context_to_sid(value, size, &newsid);
2166 if (rc)
2167 return rc;
2168
2169 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2170 FILE__RELABELTO, &ad);
2171 if (rc)
2172 return rc;
2173
2174 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2175 isec->sclass);
2176 if (rc)
2177 return rc;
2178
2179 return avc_has_perm(newsid,
2180 sbsec->sid,
2181 SECCLASS_FILESYSTEM,
2182 FILESYSTEM__ASSOCIATE,
2183 &ad);
2184}
2185
2186static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2187 void *value, size_t size, int flags)
2188{
2189 struct inode *inode = dentry->d_inode;
2190 struct inode_security_struct *isec = inode->i_security;
2191 u32 newsid;
2192 int rc;
2193
2194 if (strcmp(name, XATTR_NAME_SELINUX)) {
2195 /* Not an attribute we recognize, so nothing to do. */
2196 return;
2197 }
2198
2199 rc = security_context_to_sid(value, size, &newsid);
2200 if (rc) {
2201 printk(KERN_WARNING "%s: unable to obtain SID for context "
2202 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2203 return;
2204 }
2205
2206 isec->sid = newsid;
2207 return;
2208}
2209
2210static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2211{
1da177e4
LT		 2212 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2213}
2214
2215static int selinux_inode_listxattr (struct dentry *dentry)
2216{
2217 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2218}
2219
2220static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2221{
2222 if (strcmp(name, XATTR_NAME_SELINUX)) {
2223 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2224 sizeof XATTR_SECURITY_PREFIX - 1) &&
2225 !capable(CAP_SYS_ADMIN)) {
2226 /* A different attribute in the security namespace.
2227 Restrict to administrator. */
2228 return -EPERM;
2229 }
2230
2231 /* Not an attribute we recognize, so just check the
2232 ordinary setattr permission. Might want a separate
2233 permission for removexattr. */
2234 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2235 }
2236
2237 /* No one is allowed to remove a SELinux security label.
2238 You can change the label, but all data must be labeled. */
2239 return -EACCES;
2240}
2241
d381d8a9
JM		 2242/*
2243 * Copy the in-core inode security context value to the user. If the
2244 * getxattr() prior to this succeeded, check to see if we need to
2245 * canonicalize the value to be finally returned to the user.
2246 *
2247 * Permission check is handled by selinux_inode_getxattr hook.
2248 */
2249static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2250{
2251 struct inode_security_struct *isec = inode->i_security;
2252 char *context;
2253 unsigned len;
2254 int rc;
2255
d381d8a9
JM		 2256 if (strcmp(name, XATTR_SELINUX_SUFFIX)) {
2257 rc = -EOPNOTSUPP;
2258 goto out;
2259 }
1da177e4
LT		 2260
2261 rc = security_sid_to_context(isec->sid, &context, &len);
2262 if (rc)
d381d8a9 2263 goto out;
1da177e4 2264
d381d8a9 2265 /* Probe for required buffer size */
1da177e4 2266 if (!buffer || !size) {
d381d8a9
JM		 2267 rc = len;
2268 goto out_free;
1da177e4 2269 }
d381d8a9 2270
1da177e4 2271 if (size < len) {
d381d8a9
JM		 2272 rc = -ERANGE;
2273 goto out_free;
2274 }
2275
2276 if (err > 0) {
2277 if ((len == err) && !(memcmp(context, buffer, len))) {
2278 /* Don't need to canonicalize value */
2279 rc = err;
2280 goto out_free;
2281 }
2282 memset(buffer, 0, size);
1da177e4
LT		 2283 }
2284 memcpy(buffer, context, len);
d381d8a9
JM		 2285 rc = len;
2286out_free:
1da177e4 2287 kfree(context);
d381d8a9
JM		 2288out:
2289 return rc;
1da177e4
LT		 2290}
2291
2292static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2293 const void *value, size_t size, int flags)
2294{
2295 struct inode_security_struct *isec = inode->i_security;
2296 u32 newsid;
2297 int rc;
2298
2299 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2300 return -EOPNOTSUPP;
2301
2302 if (!value || !size)
2303 return -EACCES;
2304
2305 rc = security_context_to_sid((void*)value, size, &newsid);
2306 if (rc)
2307 return rc;
2308
2309 isec->sid = newsid;
2310 return 0;
2311}
2312
2313static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2314{
2315 const int len = sizeof(XATTR_NAME_SELINUX);
2316 if (buffer && len <= buffer_size)
2317 memcpy(buffer, XATTR_NAME_SELINUX, len);
2318 return len;
2319}
2320
2321/* file security operations */
2322
2323static int selinux_file_permission(struct file *file, int mask)
2324{
2325 struct inode *inode = file->f_dentry->d_inode;
2326
2327 if (!mask) {
2328 /* No permission to check. Existence test. */
2329 return 0;
2330 }
2331
2332 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2333 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2334 mask |= MAY_APPEND;
2335
2336 return file_has_perm(current, file,
2337 file_mask_to_av(inode->i_mode, mask));
2338}
2339
2340static int selinux_file_alloc_security(struct file *file)
2341{
2342 return file_alloc_security(file);
2343}
2344
2345static void selinux_file_free_security(struct file *file)
2346{
2347 file_free_security(file);
2348}
2349
2350static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2351 unsigned long arg)
2352{
2353 int error = 0;
2354
2355 switch (cmd) {
2356 case FIONREAD:
2357 /* fall through */
2358 case FIBMAP:
2359 /* fall through */
2360 case FIGETBSZ:
2361 /* fall through */
2362 case EXT2_IOC_GETFLAGS:
2363 /* fall through */
2364 case EXT2_IOC_GETVERSION:
2365 error = file_has_perm(current, file, FILE__GETATTR);
2366 break;
2367
2368 case EXT2_IOC_SETFLAGS:
2369 /* fall through */
2370 case EXT2_IOC_SETVERSION:
2371 error = file_has_perm(current, file, FILE__SETATTR);
2372 break;
2373
2374 /* sys_ioctl() checks */
2375 case FIONBIO:
2376 /* fall through */
2377 case FIOASYNC:
2378 error = file_has_perm(current, file, 0);
2379 break;
2380
2381 case KDSKBENT:
2382 case KDSKBSENT:
2383 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2384 break;
2385
2386 /* default case assumes that the command will go
2387 * to the file's ioctl() function.
2388 */
2389 default:
2390 error = file_has_perm(current, file, FILE__IOCTL);
2391
2392 }
2393 return error;
2394}
2395
2396static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2397{
2398#ifndef CONFIG_PPC32
2399 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2400 /*
2401 * We are making executable an anonymous mapping or a
2402 * private file mapping that will also be writable.
2403 * This has an additional check.
2404 */
2405 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2406 if (rc)
2407 return rc;
2408 }
2409#endif
2410
2411 if (file) {
2412 /* read access is always possible with a mapping */
2413 u32 av = FILE__READ;
2414
2415 /* write access only matters if the mapping is shared */
2416 if (shared && (prot & PROT_WRITE))
2417 av |= FILE__WRITE;
2418
2419 if (prot & PROT_EXEC)
2420 av |= FILE__EXECUTE;
2421
2422 return file_has_perm(current, file, av);
2423 }
2424 return 0;
2425}
2426
2427static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2428 unsigned long prot, unsigned long flags)
2429{
2430 int rc;
2431
2432 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2433 if (rc)
2434 return rc;
2435
2436 if (selinux_checkreqprot)
2437 prot = reqprot;
2438
2439 return file_map_prot_check(file, prot,
2440 (flags & MAP_TYPE) == MAP_SHARED);
2441}
2442
2443static int selinux_file_mprotect(struct vm_area_struct *vma,
2444 unsigned long reqprot,
2445 unsigned long prot)
2446{
2447 int rc;
2448
2449 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2450 if (rc)
2451 return rc;
2452
2453 if (selinux_checkreqprot)
2454 prot = reqprot;
2455
2456#ifndef CONFIG_PPC32